According to the octet rule noble gases should not form compounds but xenon and krypton form compounds like $\ce{XeF2}$, $\ce{XeF4}$, $\ce{XeOF2}$ and $\ce{KrF2}$ respectively. Why?

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    $\begingroup$ This question and its answers should apply to your question. It's a slightly different context but the idea is the same: the octet rule is rather useless beyond Period 2. $\endgroup$ Oct 17, 2015 at 15:04
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    $\begingroup$ Basically, the octet rule only applies to a very specific subset of possible compounds. In general, there is no octet rule. $\endgroup$
    – bon
    Oct 17, 2015 at 15:06
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    $\begingroup$ Nobody told Xe or Kr that they had to follow the octet rule (which is more of a rough guide than a rule). Chemistry has many 'rules' that only apply in limited circumstances. Don't blindly apply rules. $\endgroup$
    – Jon Custer
    Oct 17, 2015 at 15:50
  • $\begingroup$ See my answer to the question ortho linked to learn more about the octet rule. Also, all compounds (e.g. $\ce{XeF2, KrF2}$) with noble gases are conforming with the octet rule if applied correctly. $\endgroup$
    – Jan
    Oct 17, 2015 at 18:05

1 Answer 1


When we say that noble gases are stable it means that they are more stable than the rest. Yet it is to be considered that even these have ionisation potential ;though high. if we make a noble gases react with such ions that help in their bonding then we can have a compound of noble gas. Search this on Google.

The first published report, in June 1962, of a noble gas compound was by Neil Bartlett, who noticed that the highly oxidising compound platinum hexafluoride ionised O2 to O+ 2. As the ionisation energy of O2 to O+ 2 (1165 kJ mol−1) is nearly equal to the ionisation energy of Xe to Xe+ (1170 kJ mol−1), he tried the reaction of Xe with PtF6. This yielded a crystalline product, xenon hexafluoroplatinate, whose formula was proposed to be Xe+ [PtF 6]− . It was later shown that the compound is actually more complex, containing both XeFPtF5 and XeFPt2F11. - Wikipedia, noble gas compounds

This was the first real compound of any noble gas.


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